The invention concerns equipment for drying bales of forage regardless of their shape, which is usually round or square.
It is known that there is a need to dry forage after it has been harvested and arranged in bales of various shapes and sizes, such as for instance round or square, and this to take the forage to a controlled humidity content, for instance of around 15-18%, in order to avoid mould formation or fermentation starting that can lead to hindering the use of stored forage or nevertheless can lead to alimentary problems for the animals or even cause fires by spontaneous combustion of forage stored in barns.
The need to rationalize treatment plants and to avoid enormous structures, has given rise to the production of forage drying plants that can simultaneously treat at least two layers of bales blown by countercurrent airflows.
According to Italian patent IT 1259172 an existing dryer for round bales is described, which has a bottom chamber with several perforated compartments where the round bales are placed and a top chamber kept apart by a hollow, telescopic column and substantially the same as the bottom chamber. The two layers of bales are stacked one over the other and countercurrent airflows fed from the bottom chamber and the top chamber are used to dry the bales being treated.
One of the inconveniences that can be noted with this type of solution is that when the bales have anything other than a round shape, the plant described above does not satisfy the prerequisite of effectively drying since it has round air outlet holes, the corners for instance of a square bale, do not receive a correct drying action.
On the other hand there is a need to achieve optimum rationalization of drying plants in order to make them versatile and also functional for operators who use different kinds of forage harvesting machinery or in other words such machinery that produces round bales or square bales, for example by the use of presses with square sections.
In an attempt to overcome said inconvenience a dryer for bales of hay has been produced under international patent WO97/40330, which is provided with special adapters that, by changing the outlet air hole sections from circular to polygonal, optimize use of the dryer also for square shaped bales or, more generally, bales having other shapes than cylindrical.
The dryer produced according to the descriptions in the aforesaid international patent also have the advantage of developing in height thereby creating two floors of treatment, one stacked over the other, which reduces the overall dimensions of the plant against other equivalent plants.
However even the plant under said patent has a limitation, consisting in the impossibility to use only one of its treatment units.
This invention intends to overcome even this acknowledged limitation found in the aforesaid treatments plants with several units stacked over one another.
In particular a first scope of the invention is to produce a dryer made up of two treatment units stacked one over the other where the bottom treatment unit can even function independently to its overlying top treatment unit.
Another scope is to produce equipment for drying bales of forage that is universal, in other words that can basically achieve optimum drying of both round bales and square bales.
Moreover the intention is to make the changeover from treating round bales to treating square bales, or vice-versa, using the minimum amount of time and without requiring specialist personnel for changing the equipment.
Another intended scope is that the equipment under this invention can moreover even treat round and square bales at the same time.
Last but not least, a scope is to be able to provide equipment that does not require roofing or other constructions for protecting it from weathering.
All these scopes and others that will be better explained below are achieved by equipment for drying bales of forage comprising:
at least one unit for generating hot air equipped with a fan group that channels hot air onto
at least one pair of treatment units stacked one over the other, each having a bottom chamber and a top chamber basically rectangular in shape, kept apart by spacing devices supporting the top chamber above the bottom, and where one or more telescopic columns set between the bottom chamber and the top chamber transfer the hot air from the bottom chamber to the top one, said telescopic columns being operated by said spacer devices,
said bales being set in each treatment unit between the bottom chamber and the top chamber stacked in two layers, so that they can be dried by the countercurrent flow of hot air,
wherein one or more of said telescopic columns is provided with shutoff dampers suited to opening/closing the air flow from the bottom treatment unit to the top treatment unit.
Under the invention each of the two, bottom and top chambers should preferably be box shaped having a surface where one or more basically flat metal panels are removably connected and having holes shaped according to the type of bale undergoing the drying treatment.
An advantage of this invention is that the metal panels may have a series of circular holes to host the round bales when the equipment is being used to put round bales through the drying treatment. Otherwise the metal panels can be replaced, both on the top chamber and the bottom one, so that they have basically rectangular holes suited to supporting and hosting square shaped bales according to the sizes currently in use.